Hi, just made a du and now kde does
a) not display frames for the windows (and no system bar)
b) almost any keyboard shortcut doesn't work - except for CTRL-ESC - but neither alt-f4 or alt-tab for taskswitching or CTRL-f4 for closing a window.
c) resizing of a window will not work.

The systemsettings are ok. But I had to start fluxbox in order to work with the machine.

I think I can live with fluxbox for a couple of hours but would love to work with kde

.xsession-errors showed an error about my $HOME directory : unable to write to $HOME directory
Indeed, my $HOME directory was belonging to "501 staff" !!!
After changing user and group with the real owner, KDE is fine again

I certainly made a bad handling who changed the owner and group of my $HOME directory (probably by decompressing archives too quickly in the wrong place As penance, I'm eating a microsoft press book )
I had my KDE inoperable when I restarted the computer next day.